1. Field of the Invention
The invention relates to an audio/video cable.
2. Description of the Related Art
In recent science and technology, electricity is used for everything, such as for electric power as a drive source or for electric signal, and a conductor of a cable or a lead wire, etc., is used for transmission thereof. A metal having a high conductivity such as silver or copper, etc., is used as a material of the conductor, and especially a copper wire is used very often in view of the cost, etc.
Even though it is generically called copper, it is broadly classified into hard copper and soft copper depending on a molecular arrangement thereof. Copper of the type having desired properties is used depending on the purpose of use.
A hard copper wire is often used for a lead wire for electronic component but the rigid hard copper wire is not suitable as a cable used in electronic devices such as medical equipment, industrial robot or notebook computer since it is used in an environment where a combined external force of extreme bending, torsion and tension, etc., is repeatedly applied, and thus, a soft copper wire is used instead.
A conductor used for such a purpose is required to have contradictory characteristics, a good conductive property (high conductivity) and good bending characteristics, and thus, a copper material maintaining a high conductivity and flexibility has been developed.
For example, a flexible cable conductor having good tensile strength, elongation and conductivity is known in which a wire rod is formed of especially a copper alloy made of oxygen-free copper with a purity of not less than 99.99 wt % including 0.05 to 0.70 mass % of indium with a purity of not less than 99.99 wt % and 0.0001 to 0.003 mass % of P with a purity of not less than 99.9 wt % (see, e.g., JP-A 2002-363668).
An audio/video cable includes an audio cable, a video cable, a speaker cable, an S-terminal video cable, a D-terminal video cable and an HDMI cable, etc. For example, an audio cable is used for, e.g., reproducing stereophonic sound from a CD player through an amplifier. Meanwhile, a video cable is used for, e.g., reproducing video image and stereophonic sound from a DVD player or a video cassette recorder on a stereo television. In addition, a speaker cable is used for, e.g., reproducing sound from an amplifier through a speaker.
In addition, an S-terminal video cable is used for, e.g., reproducing an S-video image from a HDD/DVD recorder, etc., on a stereo television with an S-terminal, a D-terminal video cable is used for, e.g., reproducing a video image from a HDD/DVD recorder or a digital broadcast tuner on a stereo television with a D-terminal, and an HDMI cable is used for, e.g., reproducing a video image and sound from a HDD/DVD recorder with an HDMI terminal on a stereo television with an HDMI terminal.
The type of copper used for a conductor of such cables includes tough pitch copper (TPC), oxygen-free copper (OFC), linear crystal oxygen-free copper (LC-OFC), pure crystal oxygen free copper (PCOCC) and OFC with a purity of 99.9999% (6N) (6N-OFC), etc. There is an idea to use these materials for a hard copper wire. It is because it is considered that the sound and image quality is less deteriorated since the longer the average length of crystal grain, the less the transmission loss of a cable is.